This invention relates to a control circuit for automatically monitoring, dispensing, and filling a liquid in a container which is particularly useful in the field of photography.
In processing films in photographic work, chemicals are required and are available in a premixed condition. However, when the usage is great, for example in commercial work, a concentrate is normally used which requires accurate mixing with water. In such systems, a concentrate of the developer or fixer is placed in a container, and then a measured amount of water is added. The mixed developer and fixer in such commercial systems are drained from the bottom of the tank, and the user is usually not aware that he has used up most of the mix until nothing is left in the tank. When the tank or container is empty, the user must add concentrate and measure out the proper amount of dilutant. This process is time consuming, and subject to inaccuracies in mixing, which is a function of the care which the user takes in doing the measuring and filling.
Accordingly, it is an object of this invention to provide a new and novel control system for automatically monitoring, dispensing, and filling a liquid in a container which is accurate, reliable, saves time, and eliminates human error.